The invention refers to a fleece layering apparatus for forming a fibrous fabric web consisting of several layers of fleece, with delivery means depositing the infed web of fleece, made up of textile fibers, in a zig-zag manner onto a moveable support or on a web of fleece already laid on the support, said means being arranged on a carriage which can reciprocate between two end positions, and with delivery belts supporting the continuously infed fleece, transporting it and storing it at intervals.
Two types of fleece layering devices have been used hitherto for the production of fibrous fabric webs, these being the vertical-arm layering apparatus or the camel-hump crosslayering device, where the infed fleece is transported by delivery belts to a position high above the fibrous web to be formed and then transported by two delivery belts downwards to a carriage swinging in back and forth motion above the fibrous web, said carriage having cuttling rollers.
Fleece layering devices of this type have a range of disadvantages. On the one hand the reciprocating mass is relatively large which means that the performance is limited and on the other hand a fiber ridge forms on the edges of the fibrous web, as, at the reversing points of the carriage, during the back and forwards motion, the web of fleece is fed in at a constant speed, whereas the carriage is, at this point, stationary for a moment, and before and after this point has a delay and acceleration phase. Furthermore, at the changeover points of the fleece from one delivery belt to the other, the fleece is stretched and upset which leads to inhomogeneity of the fleece.
The second type of fleece layering device is the flat layering device which has a smaller structural height. The disadvantages with these fleece layering devices is the relatively large mass which has to undergo reciprocal motion. These devices have the advantage over the vertical-arm layering apparatus in that the fleece stretching and upsetting is slighter, however the formation of edge ridges is still not avoided.
With an improved flat cuttling device of the type in question, the web of fleece, from the infeeding to the output point, is led in a constant manner between two parallel arranged delivery belts, thus protecting the fleece which is sensitive to air turbulences, and thus enabling high delivery speeds. Furthermore, the fleece discharge speed is so controlled that it is zero at the reversing points of the carriage, so as to avoid thickening in the area of the fibrous fabric web edges. These flat layering devices however have the very great disadvantage that they require a great mechanical expenditure and large masses still have to undergo reciprocal motion. This is seen in particular in that the delivery belts guiding the web of fleece are usually 2.5 meters in width. This can have the disadvantageous effect in operation that, particularly during high speeds, air is drawin in between the belts forming air pockets which impair the bond of the fleece and cause defects.